A chemical pollution incident in Mangniu River, a Songhua River tributary which runs through the city of Jilin, in northeast China's Jilin Province, was brought under control Wednesday, said the local environmental protection bureau.

Experts arriving at the river were greeted with the sight of a five-kilometer-long pollution slick of bubbly, red water.

Preliminary tests indicate that the major pollutant is xylidine.

The city government launched emergency plans and officials from the State Environmental Protection Administration, the Jilin provincial government and the provincial environmental protection bureau rushed to the polluted sector of the tributary to organize pollution control.

More than 1,000 army personnel and fire fighters built a pollution interception dam and two dams with activated carbon to absorb the pollutants.

Through filtration, the stretch of polluted water had bypassed the three dams and flowed into the Songhua River.

No pollutants have so far been detected in the Songhua River, according to the city's environmental protection bureau.

Preliminary investigations show that the pollutants contained in water were illegally discharged by Changbaishan Jingxi ChemicalCo. Company personnel responsible for the pollution have been detained.